Generally, the smaller the particle sizes of emulsions are, the higher their stability in aqueous solutions is. There are known several methods to obtain emulsions having small particle sizes by the addition of polyhydric alcohols to mixtures in which oily phases and nonionic surfactants have been dissolved followed by the emulsification thereof (Japanese Unexamined Patent Publication (Kokai) No. 62-250941, Japanese Examined Patent Publication (Kokoku) No. 63-61050, and Japanese Unexamined Patent Publication (Kokai) No. 63-107740). However, the particle sizes of the emulsions obtained by these methods are not small enough and hence it was difficult to secure stability in low-viscosity aqueous solutions. An alternative method for reducing particle sizes involves the use of a high-pressure homogenizer which exerts forcefully a physically great power to emulsions. But this requires extensive equipment, which significantly contributed to high cost of the method. Furthermore, although the emulsions obtained in this method are relatively stable in aqueous solutions having near-neutral pH or low concentrations of ionic substances, they have the problem of being unstable in aqueous solutions of pH 2.5-5.0 which are often used for medicinal beverages, refreshing beverages, etc., in aqueous solutions which contain inorganic salts, salts of organic acids and the like and which have high concentrations of ionic substances as high as 0.1-5% by weight, and thereby are easy to form creams, precipitates or the like.